- WK - JEEP GRAND CHEROKEE -.L V TURBO DIESEL P44-DIESEL PARTICULATE FILTER CIRCUIT LOW. GAS F88 GY/YL K94 OR K GY/BK K K9 K4 BR/DG BK/DB BR/LG 8 C GAS VOLT SUPPLY 9 C GAS GROUND 8 C GAS SIGNAL C SIGNAL C GROUND C VOLT SUPPLY CONTROL 48 4 4 9 9 8 4 49 CONTROL C GAS CONTROL C 8888afc For a complete wiring diagram Refer to the Wiring Information Theory of Operation The Diesel particulate filter is an inline canister filter located in the exhaust system between the engine and the muffler. This filter captures and stores ash particles created by the diesel combustion process. This filter is monitored by the
ECM with a Differential Pressure Sensor. This sensor measures the difference in exhaust system pressure before and after the particulate filter through tube connections directly to the exhaust pipe. As ash accumulates in the filter, the exhaust pressure at the inlet side of the filter increases as compared to the pressure at the outlet side of the filter. The ECM monitors the sensor to determine when to perform a particulate filter regeneration procedure which is designed to clear or burn-off the ash collected in the filter. When Monitored: With the ignition on. Set Condition: The (K) Exhaust Differential Pressure Sensor signal is below.4 volts for. seconds. INTERMITTENT DTC Possible Causes (K4) VOLT SUPPLY CIRCUIT SHORTED TO GROUND (K) SIGNAL CIRCUIT SHORTED TO GROUND (K4) VOLT SUPPLY CIRCUIT SHORTED TO (K9) GROUND CIRCUIT (K) SIGNAL CIRCUIT SHORTED TO (K9) GROUND CIRCUIT (K4) VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE (K) SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE CONTROL MODULE (ECM) Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.(refer to 8 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure). DTC IS ACTIVE. Ignition on, engine not running.. With the scan tool, Clear DTCs in the Engine Control Module (ECM).. Monitor the scan tool for at least two minutes. 4. Cycle the ignition key off and on several times, leaving the ignition on for at least seconds at a time.. Start the engine.. Allow the engine to reach normal operating temperature.. With the scan tool, select View DTCs. Is the status Active for this DTC? Yes Go To No Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.(Refer to 8 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure)
. (K4) VOLT SUPPLY CIRCUIT VOLTAGE. Turn the ignition off.. Disconnect the Exhaust Differential Pressure Sensor. Turn the ignition on. 4. Measure the voltage of the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit in the Exhaust Differential Pressure Sensor V Is the voltage above 4. volts? Yes Go to No Go to 94. (K4) VOLT SUPPLY CIRCUIT SHORTED TO GROUND. Turn the ignition off.. Disconnect the Engine Control Module (ECM) harness connector.. Measure the resistance between ground and the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit in the Exhaust Differential Pressure Sensor Is the resistance above ohms? Yes Go to 4 No Repair the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit for a short to ground. Perform the ECM Verification Test(Refer to 8
4. (K4) VOLT SUPPLY CIRCUIT SHORTED TO (K9) GROUND CIRCUIT. Measure the resistance between the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit and the (K9) Exhaust Differential Pressure Sensor Ground circuit in the Exhaust Differential Pressure Sensor Is the resistance above ohms? Yes Go to No Repair the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit for a short to the (K9) Exhaust Differential Pressure Sensor Ground circuit. Perform the ECM Verification Test(Refer to 8. (K4) VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE. Measure the resistance of the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit between the Exhaust Differential Pressure Sensor harness connector and the Engine Control Module (ECM) Is the resistance below. ohms? Yes Go to No Repair the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit for an open circuit or high resistance. Perform the ECM Verification Test(Refer to 8 9 8 4 CONTROL C 4 4
. (K) SIGNAL CIRCUIT SHORTED TO GROUND. Turn the ignition off.. Disconnect the Engine Control Module (ECM) harness connector.. Measure the resistance between ground and the (K) Exhaust Differential Pressure Sensor Signal circuit in the Exhaust Differential Pressure Sensor harness connector. Is the resistance above ohms? Yes Go to 9 8 No Repair the (K) Exhaust Differential Pressure Sensor Signal circuit for a short to ground. Perform the ECM Verification Test(Refer to 8 CONTROL C 4. (K) SIGNAL CIRCUIT SHORTED TO (K9) GROUND CIRCUIT. Measure the resistance between the (K) Exhaust Differential Pressure Sensor Signal circuit and the (K9) Exhaust Differential Pressure Sensor Ground circuit in the Exhaust Differential Pressure Sensor Is the resistance above ohms? Yes Go to 8 No Repair the (K) Exhaust Differential Pressure Sensor Signal circuit for a short to the (K9) Exhaust Differential Pressure Sensor Ground circuit. Perform the ECM Verification Test(Refer to 8
8. (K) SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE. Measure the resistance of the (K) Exhaust Differential Pressure Sensor Signal circuit between the Exhaust Differential Pressure Sensor harness connector and the Engine Control Module (ECM) Is the resistance below. ohms? Yes Go to 9 No Repair the (K) Exhaust Differential Pressure Sensor Signal circuit for an open circuit or high resistance. 9 8 Perform the ECM Verification Test(Refer to 8 4 CONTROL C 9.. Turn the ignition off.. Connect the Engine Control Module (ECM). Connect a jumper wire between the (K4) Exhaust Differential Pressure Sensor Volt Supply circuit and the (K) Exhaust Differential Pressure Sensor Signal circuit in the Exhaust Differential Pressure Sensor 4. Turn the ignition on.. With the scan tool, Clear DTCs.. With the scan tool, select View DTCs. NOTE: The scan tool should display an Exhaust Differential Pressure Sensor high voltage or open DTC with the Exhaust Differential Pressure Sensor connector disconnected and the jumper wire in place. Does the scan tool display the DTC as described above? Yes Replace the Exhaust Differential Pressure Sensor in accordance with the Service Information. Perform the ECM Verification Test(Refer to 8 Control (ECM) - Standard Procedure). No Go to. CONTROL MODULE (ECM). Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Exhaust Differential Pressure Sensor and the Engine Control Module (ECM).. Look for any chafed, pierced, pinched, or partially broken wires.. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.. Look for the data to change or for the DTC to reset during the wiggle test.. Refer to any Technical Service Bulletins that may apply. Were any problems found? Yes Repair as necessary. Perform the ECM Verification Test(Refer to 8 Control (ECM) - Standard Procedure). No Replace the Engine Control Module (ECM) in accordance with the Service Information. Perform the ECM Verification Test(Refer to 8 Control (ECM) - Standard Procedure).